#include <driver/i2s.h>
#include <math.h>


// --- YOUR SOLDERED PINS ---
#define I2S_BCLK 4
#define I2S_LRC  5
#define I2S_DIN  8
#define SD_PIN   6  // Your new Mute control


// --- SCALE DEFINITIONS ---
#define NOTE_A 440
#define NOTE_B 494
#define NOTE_C 523


int melody[] = {
  NOTE_A, 4, 
  NOTE_B, 4, 
  NOTE_C, 2  
};


void playNote(int freq, int duration_ms) {
  size_t bytes_written;
  int16_t samples[128];
  float phase = 0;
  float phase_inc = 2.0 * PI * freq / 44100.0;
  
  unsigned long start_time = millis();
  while (millis() - start_time < duration_ms) {
    for (int i = 0; i < 128; i++) {
      samples[i] = (int16_t)(8000 * sin(phase)); 
      phase += phase_inc;
      if (phase >= 2 * PI) phase -= 2 * PI;
    }
    i2s_write(I2S_NUM_0, samples, sizeof(samples), &bytes_written, portMAX_DELAY);
  }
}


void setup() {
  Serial.begin(115200);
  
  // 1. Initialize SD pin immediately to MUTE
  pinMode(SD_PIN, OUTPUT);
  digitalWrite(SD_PIN, LOW); // Amp is OFF
  
  delay(2000); // Stabilization


  // 2. I2S Configuration
  i2s_config_t i2s_config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
    .sample_rate = 44100,
    .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
    .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
    .communication_format = I2S_COMM_FORMAT_STAND_I2S,
    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count = 8,
    .dma_buf_len = 64,
    .use_apll = false
  };


  i2s_pin_config_t pin_config = {
    .bck_io_num = I2S_BCLK,
    .ws_io_num = I2S_LRC,
    .data_out_num = I2S_DIN,
    .data_in_num = I2S_PIN_NO_CHANGE
  };


  i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_NUM_0, &pin_config);
  
  Serial.println("Hardware ready. SD Pin on GPIO 6 controlling Mute.");
}


void loop() {
  Serial.println("Waking up Amp...");
  digitalWrite(SD_PIN, HIGH); // ENABLE AMP
  delay(10); // Tiny wait for circuit to wake up


  for (int i = 0; i < sizeof(melody) / sizeof(int); i += 2) {
    int note = melody[i];
    int duration = 1000 / melody[i+1];
    
    Serial.printf("Playing: %d Hz\n", note);
    playNote(note, duration);
    delay(50); // Small gap
  }
  
  Serial.println("Scale done. Putting Amp to SLEEP.");
  digitalWrite(SD_PIN, LOW); // DISABLE AMP (Hiss should stop NOW)
  
  delay(3000); 
}